Graviton resonance phenomenology and a pseudo-Nambu-Goldstone boson Higgs at the LHC

ALVAREZ, EZEQUIEL; DA ROLD, LEANDRO; MAZZITELLI, JAVIER; SZYNKMAN, ALEJANDRO

Physical Review D

American Physical society

Año: 2017 vol. 95

2470-0010

We present an effective description of a spin two massive state and a pseudo-Nambu-Goldstone bosonHiggs in a two site model. Using this framework, we model the spin-two state as a massive graviton and westudy its phenomenology at the LHC. We find that a reduced set of parameters can describe the mostimportant features of this scenario. We address the question of which channel is the most sensitive to detectthis graviton. Instead of designing search strategies to estimate the significance in each channel, wecompare the ratio of our theoretical predictions to the limits set by available experimental searches for allthe decay channels and as a function of the free parameters in the model. We discuss the phenomenologicaldetails contained in the outcome of this simple procedure. The results indicate that, for the studied massesbetween 0.5 and 3 TeV, the channels to look for such a graviton resonance are mainly ZZ, WW, and γγ. Thisis the case even though top and bottom quarks dominate the branching ratios, since their experimentalsensitivity is not as good as the one of the electroweak gauge bosons. We find that as the graviton massincreases, the ZZ and WW channels become more important because of its relatively better enhancementover background, mainly due to fat jet techniques. We determine the region of the parameter space that hasalready been excluded and the reach for the LHC next stages. We also estimate the size of the loop-inducedcontributions to the production and decay of the graviton, and show in which region of the parameter spacetheir effects are relevant for our analysis.